feat(ui): interactive chat composer state on the session monitor VM

TaskMonitorViewModel gains IsInteractiveLive + ComposerDraft + SubmitComposer
(optimistic LogKind.User echo, then SendInteractiveMessageAsync) + StopInteractive,
driven by the InteractiveSessionStarted/Ended events. Since DetailsIslandViewModel
embeds this monitor, both task detail and Mission Control get the composer. Mission
Control auto-creates a monitor on InteractiveSessionStarted. Adds LogKind.User.

src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs

@@ -19,6 +19,7 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
     private readonly Action<string, string, string, DateTime> _onTaskFinished;
     private readonly Action<string> _onTaskUpdated;
     private readonly Action _onConnectionRestored;
+    private readonly Action<string> _onInteractiveStarted;
 
     public ObservableCollection<TaskMonitorViewModel> Monitors { get; } = new();
 
@@ -67,6 +68,14 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
         _onConnectionRestored = () => { SeedActive(); _ = RefreshQueueAsync(); };
         _worker.ConnectionRestoredEvent += _onConnectionRestored;
 
+        _onInteractiveStarted = taskId =>
+        {
+            EnsureMonitor(taskId);
+            var m = Monitors.FirstOrDefault(x => x.SubscribedTaskId == taskId);
+            m?.SetInteractiveLive(true);
+        };
+        _worker.InteractiveSessionStartedEvent += _onInteractiveStarted;
+
         SeedActive();
         _ = RefreshQueueAsync();
     }
@@ -209,6 +218,7 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
         _worker.TaskFinishedEvent -= _onTaskFinished;
         _worker.TaskUpdatedEvent -= _onTaskUpdated;
         _worker.ConnectionRestoredEvent -= _onConnectionRestored;
+        _worker.InteractiveSessionStartedEvent -= _onInteractiveStarted;
         Monitors.CollectionChanged -= OnMonitorsChanged;
         foreach (var m in Monitors) m.Dispose();
         Monitors.Clear();